I'm highly selective when it comes to people to the point I prefer to be alone than to be around the wrong people. I think many if not most people aren't compatible with me, and I'm not willing to compromise for the sake of not being alone (I have high tolerance to loneliness, although at times it strikes me). That's why I have hard times forming friendships. Yet I have the openness problem in the sense that I say things to people whom I barely know that I shouldn't say by mentioning unnecessary details. It's naive. But it happens a lot.